1. Field
This invention is in the field of quick-release bicycle axle fasteners.
2. Prior Art
Bicycle wheels are often attached to bicycles by a type of fastener which is quickly releasable without tools, to allow convenient removal of the wheel. This allows bicycle racers to quickly replace a wheel when a flat tire occurs. It also allows convenient wheel removal for attachment of bicycles to some types of bike racks, and for compact storage.
Conventional quick-release bicycle axle fasteners (QRs) trade convenience for safety. The release mechanism is usually a lever-operated cam, which can be inadvertently left open, causing the wheel to disengage from the bicycle unexpectedly. To solve this problem the axle mounting plates, or drop-outs, on bicycles now have a safety retention surface which retains the fastener even when the cam is loose. This is a depression or safety tab on the outer surface of each dropout, which retains the cam tension adjustment nut and cam follower of the fastener. To disengage the fastener from the retention surface, the adjustment nut must be loosened. This means the conventional QR must be readjusted each time the axle is reinstalled. This adjustment is often done incorrectly by the average user, resulting in riding accidents due to wheel disengagement.
Earlier attempts to solve this problem have not been successful, either because they were an incomplete solution, were inconvenient, expensive, or had other disadvantages, such as alternate safety problems.
The best solution to date has come from inventor Cal M. Phillips, who added a safety-interlock slide inboard and around the cam adjustment nut. When the cam is open, the slide is urged inward against the safety drop-out by a spring. When the cam is dosed, the slide stops outward against the adjustment nut, providing full clamping force. Cam adjustment is made with a wrench on the adjustment nut when the axle is first installed in the drop-outs. The nut is not subsequently loosened for each operation of the fastener. The cam has a large enough throw to clear both safety retention tabs without assistance of the adjustment nut. To release the fastener, the user opens the cam, then pulls the slide outward with the fingers while pressing the adjustment nut with the thumb, as with a hypodermic needle. This releases both ends of the fastener from the safety tabs on the dropouts, providing a quick, convenient, safe QR. The only additional action required for operation is simultaneously pressing the adjustment nut and pulling the slide outward with the fingers. This additional action is eliminated by the present invention.